The 14-foot-tall corrugated metal wall concealing a vacant corner lot on Newkirk Avenue and Marlborough Road is not enough to contain a world of trouble, its neighbors say.

“We want the wall down,” Sally Li said as she looked through the window of her bar-restaurant across the street.

The lot—once the site of a gas station—has drawn nearly $100,000 in city fines and, merchants and residents say, is a source of a persistent rat problem.